Wireless communication networks have evolved from pure voice networks to high-speed data networks. The 4th generation radio network long-term evolution, LTE, is able to provide capacities exceeding 100 Mbit/s in an ultra-dense small-cell installation. As most of the traffic in the wireless communication networks will be generated in-doors, ultra-dense small-cell indoor network solutions are required. Different approaches have been taken to provide network architectures able to cost-efficiently and reliably meet the run on high mobile capacity.
One such approach is to re-use existing metallic conductors in buildings, such as copper cables, e.g. Ethernet cables, and to employ a distributed base station system comprising a base band unit, BBU, and a plurality of radio heads, RH. The BBU would communicate with the plurality of RHs via the metallic conductors; one metallic conductor may be connected to one RH. Such a system may be called a Radio over Copper, RoCU, system.
The metallic conductors in a RoCU system may be placed physically close to other cabling carrying legacy services such as Ethernet traffic. For example, the metallic conductors of a RoCU system may be placed in the same cable bundle as the cabling carrying legacy services. Such scenarios may cause crosstalk between the metallic conductors of the RoCU system and the cabling carrying legacy services. Crosstalk is a disturbance wherein signals sent over one metallic conductor causes disturbances to signals sent in another metallic conductor. Crosstalk may occur in this case if the RoCU system uses a frequency bandwidth that overlaps with the frequency bandwidth used by the legacy service. Crosstalk may cause degradation to the signals sent in the system experiencing the disturbance. It can either be so that the transmission over the metallic conductors of the RoCU system are degraded due to crosstalk from the legacy service traffic, or vice versa.
Consequently, there is a need to prevent such crosstalk or at least reduce such crosstalk between metallic conductors of a RoCU system and metallic conductors of another communication system.